mail::mbox::messageparser::cache(3) [suse man page]
Mail::Mbox::MessageParser::Cache(3) User Contributed Perl Documentation Mail::Mbox::MessageParser::Cache(3)NAME
Mail::Mbox::MessageParser::Cache - A cache-based mbox folder reader
SYNOPSIS
#!/usr/bin/perl
use Mail::Mbox::MessageParser;
my $filename = 'mail/saved-mail';
my $filehandle = new FileHandle($filename);
# Set up cache
Mail::Mbox::MessageParser::SETUP_CACHE(
{ 'file_name' => '/tmp/cache' } );
my $folder_reader =
new Mail::Mbox::MessageParser( {
'file_name' => $filename,
'file_handle' => $filehandle,
'enable_cache' => 1,
} );
die $folder_reader unless ref $folder_reader;
warn "No cached information"
if $Mail::Mbox::MessageParser::Cache::UPDATING_CACHE;
# Any newlines or such before the start of the first email
my $prologue = $folder_reader->prologue;
print $prologue;
# This is the main loop. It's executed once for each email
while(!$folder_reader->end_of_file());
{
my $email = $folder_reader->read_next_email();
print $email;
}
DESCRIPTION
This module implements a cached-based mbox folder reader. It can only be used when cache information already exists. Users must not
instantiate this class directly--use Mail::Mbox::MessageParser instead. The base MessageParser module will automatically manage the use of
cache and non-cache implementations.
METHODS AND FUNCTIONS
The following methods and functions are specific to the Mail::Mbox::MessageParser::Cache package. For additional inherited ones, see the
Mail::Mbox::MessageParser documentation.
$ref = new( { 'file_name' => <mailbox file name>, 'file_handle' => <mailbox file handle>, });
<file_name> - The full filename of the mailbox
<file_handle> - An opened file handle for the mailbox
The constructor for the class takes two parameters. file_name is the filename of the mailbox. This will be used as the cache key, so
it's important that it fully defines the path to the mailbox. The file_handle argument is the opened file handle to the mailbox. Both
arguments are required.
Returns a reference to a Mail::Mbox::MessageParser object, or a string describing the error.
BUGS
No known bugs.
Contact david@coppit.org for bug reports and suggestions.
AUTHOR
David Coppit <david@coppit.org>.
LICENSE
This software is distributed under the terms of the GPL. See the file "LICENSE" for more information.
HISTORY
This code was originally part of the grepmail distribution. See http://grepmail.sf.net/ for previous versions of grepmail which included
early versions of this code.
SEE ALSO
Mail::Mbox::MessageParser
perl v5.12.1 2009-08-09 Mail::Mbox::MessageParser::Cache(3)
Check Out this Related Man Page
Mail::Mbox::MessageParser(3pm) User Contributed Perl Documentation Mail::Mbox::MessageParser(3pm)NAME
Mail::Mbox::MessageParser - A fast and simple mbox folder reader
SYNOPSIS
#!/usr/bin/perl
use Mail::Mbox::MessageParser;
my $file_name = 'mail/saved-mail';
my $file_handle = new FileHandle($file_name);
# Set up cache. (Not necessary if enable_cache is false.)
Mail::Mbox::MessageParser::SETUP_CACHE(
{ 'file_name' => '/tmp/cache' } );
my $folder_reader =
new Mail::Mbox::MessageParser( {
'file_name' => $file_name,
'file_handle' => $file_handle,
'enable_cache' => 1,
'enable_grep' => 1,
} );
die $folder_reader unless ref $folder_reader;
# Any newlines or such before the start of the first email
my $prologue = $folder_reader->prologue;
print $prologue;
# This is the main loop. It's executed once for each email
while(!$folder_reader->end_of_file())
{
my $email = $folder_reader->read_next_email();
print $$email;
}
DESCRIPTION
This module implements a fast but simple mbox folder reader. One of three implementations (Cache, Grep, Perl) will be used depending on the
wishes of the user and the system configuration. The first implementation is a cached-based one which stores email information about
mailboxes on the file system. Subsequent accesses will be faster because no analysis of the mailbox will be needed. The second
implementation is one based on GNU grep, and is significantly faster than the Perl version for mailboxes which contain very large(10MB)
emails. The final implementation is a fast Perl-based one which should always be applicable.
The Cache implementation is about 6 times faster than the standard Perl implementation. The Grep implementation is about 4 times faster
than the standard Perl implementation. If you have GNU grep, it's best to enable both the Cache and Grep implementations. If the cache
information is available, you'll get very fast speeds. Otherwise, you'll take about a 1/3 performance hit when the Grep version is used
instead.
The overriding requirement for this module is speed. If you wish more sophisticated parsing, use Mail::MboxParser (which is based on this
module) or Mail::Box.
METHODS AND FUNCTIONS
SETUP_CACHE(...)
SETUP_CACHE( { 'file_name' => <cache file name> } );
<cache file name> - the file name of the cache
Call this function once to set up the cache before creating any parsers. You must provide the location to the cache file. There is no
default value.
new(...)
new( { 'file_name' => <mailbox file name>,
'file_handle' => <mailbox file handle>,
'enable_cache' => <1 or 0>,
'enable_grep' => <1 or 0>,
'force_processing' => <1 or 0>,
'debug' => <1 or 0>,
} );
<mailbox file name> - the file name of the mailbox
<mailbox file handle> - the already opened file handle for the mailbox
<enable_cache> - true to attempt to use the cache implementation
<enable_grep> - true to attempt to use the grep implementation
<force_processing> - true to force processing of files that look invalid
<debug> - true to print some debugging information to STDERR
The constructor takes either a file name or a file handle, or both. If the file handle is not defined, Mail::Mbox::MessageParser will
attempt to open the file using the file name. You should always pass the file name if you have it, so that the parser can cache the
mailbox information.
This module will automatically decompress the mailbox as necessary. If a filename is available but the file handle is undef, the module
will call either bzip2, or gzip to decompress the file in memory if the filename ends with .tz, .bz2, or .gz, respectively. If the file
handle is defined, it will detect the type of compression and apply the correct decompression program.
The Cache, Grep, or Perl implementation of the parser will be loaded, whichever is most appropriate. For example, the first time you
use caching, there will be no cache. In this case, the grep implementation can be used instead. The cache will be updated in memory as
the grep implementation parses the mailbox, and the cache will be written after the program exits. The file name is optional, in which
case enable_cache and enable_grep must both be false.
force_processing will cause the module to process folders that look to be binary, or whose text data doesn't look like a mailbox.
Returns a reference to a Mail::Mbox::MessageParser object on success, and a scalar desribing an error on failure. ("Not a mailbox",
"Can't open <filename>: <system error>", "Can't execute <uncompress command> for file <filename>"
reset()
Reset the filehandle and all internal state. Note that this will not work with filehandles which are streams. If there is enough
demand, I may add the ability to store the previously read stream data internally so that reset() will work correctly.
endline()
Returns "
" or "
", depending on the file format.
prologue()
Returns any newlines or other content at the start of the mailbox prior to the first email.
end_of_file()
Returns true if the end of the file has been encountered.
line_number()
Returns the line number for the start of the last email read.
number()
Returns the number of the last email read. (i.e. The first email will have a number of 1.)
length()
Returns the length of the last email read.
offset()
Returns the byte offset of the last email read.
read_next_email()
Returns a reference to a scalar holding the text of the next email in the mailbox, or undef at the end of the file.
BUGS
No known bugs.
Contact david@coppit.org for bug reports and suggestions.
AUTHOR
David Coppit <david@coppit.org>.
LICENSE
This software is distributed under the terms of the GPL. See the file "LICENSE" for more information.
HISTORY
This code was originally part of the grepmail distribution. See http://grepmail.sf.net/ for previous versions of grepmail which included
early versions of this code.
SEE ALSO
Mail::MboxParser, Mail::Box
perl v5.10.1 2010-06-06 Mail::Mbox::MessageParser(3pm)